Folding knives enjoy wide popularity, particularly among sportsmen, campers, hikers, and many others engaged in outdoor activities. Common elements to folding knives include a handle and a blade pivotally connected to an end of the handle so that the blade pivots with respect to the handle between an open position in which the blade is extended away from the handle and a closed position in which the blade is at least partially received within the handle. Many folding knives also include a locking mechanism to maintain the blade in an open position.
Examples of folding knives, including folding knives with locking mechanisms, may be found in U.S. Pat. Nos. 1,454,665; 1,743,022; 4,040,081; 4,404,748; 4,451,982; 4,502,221; 4,719,700; 4,805,303; 4,811,486; 4,837,932; 4,893,409; 4,974,323; 4,979,301; 5,044,079; 5,060,379; 5,095,624; 5,111,581; 5,293,690; 5,325,588; 5,331,741;5,425,175; 5,502,895; 5,515,610; 5,537,750; 5,615,484; 5,685,079; 5,689,885; 5,692,304; 5,737,841; 5,755,035; 5,802,722; 5,822,866; 5,826,340; 5,887,347; 5,964,036; 6,079,106; 6,154,965; 6,338,431; 6,378,214; 6,427,335; and 6,438,848; and U.S. Patent Application Nos. 2002/0157260 and 2003/0070299, the entire disclosures of which are herein incorporated by reference for all purposes.
A simple mechanism for locking and unlocking the blade of a folding knife, particularly one that may be operated with a single thumb-actuated motion while the user's hand is holding the knife, may enhance the utility of the knife. That mechanism may be of further utility if it also may be used for one-handed opening and/or closing of the blade.